iraf.net

NUMBER:	529
MODULE:	imcombine
SYSTEM:	V2.11-V2.11.3
DATE:	Mon Aug 11 12:13:29 MST 2003
FROM:	valdes

BUG:	When specifying a bad pixel mask output with the 'plfile' parameter
	it is possible to get

	    Warning: Operation would overwrite existing image (.pl)

	This occurs when a problem is encountered and the task tries again
	with a different parameters to avoid the problem.  The bug is that
	the pl file is not deleted before tryng again.  This retry behavior
	occurs for several reasons, most commonly when the number of images
	being combined exceeds a limit of about 250 images.  The workaround
	is to 'reset imclobber=yes'.  Note that this resets the clobber
	policy for all IRAF tasks so one should probably reset it to 'no'
	after working around this IMCOMBINE bug.

STATUS:	This is fixed in V2.12.